In an Internet Protocol network or IP network, i.e. in a network that uses the TCP/IP Protocol, each network device and each terminal arrangement needs a unique Internet Protocol address or IP Address. In IP version 4 (Ipv4), an IP address, which is made up of a network address and a device address, consists of four numbers (octets) each separated by a dot, for example 204.107.64.2. In later IP versions, more octets are used for the IP address. IP addresses can be created manually and permanently assigned to a terminal arrangement in a network. Manual configuration of an IP network is time consuming, however, and only of interest for smaller, rarely changed sub-networks.
To automate the assignment of IP addresses, network operators hence normally use a BOOTSTRAP protocol or BOOTP as it is known, or a Dynamic Host Configuration Protocol or DHCP. BOOTP is a TCP/IP protocol that can be used by terminal arrangements to find out their IP address or other network information such as server addresses and gateway data. When a terminal arrangement boots up, it transfers a BOOTP REQUEST to the BOOTP server in a UDP packet (USER DATA PROTOCOL, an unreliable TCP/IP protocol), said server sending back the required IP address in a BOOTP RESPONSE message.
In this procedure, the BOOTP REQUEST and BOOTP RESPONSE messages use an IP broadcast function, which can be used to send messages before the specific IP address is known. Such a method is described in detail in U.S. Pat. No. 6,115,545, for example.
DHCP is also a piece of software for automatic assignment of IP addresses to terminal devices that log into a TCP/IP network. DHCP software normally runs on servers, and such a DHCP server is described in U.S. Pat. No. 5,884,024 for example. The main way in which DHCP differs from BOOTP is that once an IP address is assigned it is stored and used again for later DHCP request messages.
In order to assign an IP address, BOOTP servers or DHCP servers require a hardware address of a terminal arrangement, which is sent by the network interface of said terminal arrangement to the respective server in the IP-address request message, e.g. in the BOOTP REQUEST. In networks based on the ETHERNET standard, the hardware address (MAC address) of the Ethernet card forming the network interface is used as a uniquely assignable identifier for each IP-address request and IP-address response (BOOTP REQUEST, BOOT RESPONSE).
Terminal arrangements in the sense intended here are, for example, network computers having Ethernet card or modem as network interface. In particular, however, terminal arrangement is also used to mean network terminating units known as Integrated Access Devices or IADs. Such an IAD is a network terminating unit for multiplexing different communications technologies at the subscriber end onto a single telecommunications network line. The IAD also demultiplexes the data streams coming from the network into the relevant channels.
A telecommunications network line for connecting to an IAD may be an analog telephone line or even an ISDN line, a DSL line or a T1 line. Currently, the most common use of IAD units is the multiplexing of voice and data over a DSL line. DSL stands for Digital Subscriber Line, and, unlike an ISDN line, is not enabled using switching technology but is permanently connected and supplied with voice information and data information via a central network device, a DSL Access Multiplexer or DSLAM for short. The DSL digital subscriber lines of a particular local area emanate from such a DSLAM, which is usually part of a peripheral network node, and a specific set of subscriber line data (port data) configurable by a central network management system is often stored in the DSLAM for each subscriber line.
A network operator can manage terminal arrangements such as IADs in an IP network centrally using SNMP over IP for instance, where SNMP stands for Simple Network Management Protocol, which is a network monitoring and control protocol used throughout the world. In order to manage a terminal arrangement, the network operator must assign the allocated network management interface a static IP address that can be used to exchange network management messages. Furthermore, the IP routers and the network management system within the IP network of the network operator must also know this IP address. Network operators do this using one of the BOOTP or DHCP protocols in the aforementioned way. The unique identifier for defining an IP address in a BOOTP server or DHCP server is the hardware address of the terminal arrangement.
When installing a terminal arrangement, the network operator must enter the required information in the BOOTP server with the hardware address of the internet protocol interface of the relevant network arrangement of the terminal arrangement used. To do this, either the exact hardware address of the terminal arrangement must be entered manually by the subscriber prior to installation, or the subscriber must register the hardware address with the network operator via telephone or post, once the terminal arrangement has been installed at the subscriber's premises. If, for example, the subscriber has not obtained the terminal arrangement from the network operator, but purchased it on the open market, then registration of the hardware address of the terminal arrangement by the subscriber is currently the only solution. Both registration options mentioned are very time consuming, require coordination between subscriber and network operator, are prone to errors and can lead to undesirable delays in service availability after the terminal arrangement has been installed at the subscriber's premises.
The object of the invention is to define a more advantageous method of assigning IP addresses for terminal arrangements, and to define suitable arrangements for this purpose.